Trimethoprim is one of the representative drugs within the pharmaceutical and personal care products (PPCPs) group. The photo-Fenton oxidation technology was used to degrade trimethoprim in wastewater and the extent of degradation was analyzed by using high-performance liquid chromatography, then experimentally obtained the optimal conditions. Analysis of the experimental data showed that, under the single-factor experimental conditions, the optimal conditions for degradation were a pH of 4, an H2O2 concentration of 3.0 mmol/L, an FeSO4 concentration of 0.06 mmol/L, an initial trimethoprim concentration of 0.0689 mmol/L, and an ultraviolet (UV) intensity (UVA) of 12 mW/cm2. The interaction of pH and the concentration of H2O2 and Fe2+ have been further explored, it was obtained the following response surface results through the central composite design experiment: pH = 4.56, H2O2 concentration = 0.09 mmol/L, and Fe2+ concentration = 0.09 mmol/L. Under these conditions, it can be obtained a degradation rate of 99.95% after 6 min. There were similar results for three sets of parallel experiments, indicating that these simulation conditions were feasible.

The outbreak of cyanobacterial blooms in water can cause serious harm to water supply safety and human health, which has become one of the major water environmental problems in the present world. In this paper, the representative Microcystis aeruginosa blooms were studied by the eutrophic microcosmic simulation device between natural lake system and test in laboratory scale. Toxic Microcystis aeruginosa FACHB-905 and non-toxic Microcystis aeruginosa FACHB-469 were used to simulate algal blooms in different nutrient conditions. The study of stratified EPS extracted from different vegetative and growth stages of Microcystis aeruginosa showed that high nutritional conditions can induce Microcystis aeruginosa to produce more extracellular polysaccharides, while low nutrient conditions can affect the fluorescence components in the SL-EPS (Soluble EPS) of Microcystis aeruginosa. Furthermore, the proteins in TB-EPS (Tightly bound EPS) will gradually release to SL-EPS and LB-EPS (loosely bound EPS) during the bloom, which can decrease from 34% in the initial growth period to 20%. The tryptophan-like substances in SL-EPS and TB-EPS, and the humic-acid-like substances in SL-EPS have a significant impact on the Microcystis aeruginosa blooms. Finally, all these results are expected to be of use in the study of the algal blooming outbreak early warning and control problems.

Sustainable development is a hot issue in ecological economy. By analyzing the grey relational grade matrix, the degree of influence for each factor on sustainable development can be found. The results showed that main factors of influencing sustainable development were total population, gross domestic product, total investment in fixed assets, per capita annual living expenditure of urban households, per capita consumption expenditure of rural households and proportion of tertiary industry in industrial composition by grey relational analysis(GRA). A three-layer artificial neural network (ANN) model was developed to predict sustainable development. The 6-4-3 ANN model with standardization transformation was the best model. GRA and ANN are useful tools to evaluate sustainable development and provide policy proposals for decision-making to local government.

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